'It's very possible to have every intent and desire to be on time, and still fail at it.'
The people who try to arrive 'just in time' are the ones this usually applies to though.
If you've ever worked at a place where you have a long commute you'll likely have noticed that the people who are consistently late are those who live closest.
People who really struggle with time management and planning, yup. The lack of an ability to reason about time - to, fundamentally, exercise executive function - leads to these problems where the time estimates are always short.
For some people, it's hard to see all the pieces ("take a shower, brush teeth, put on clothes, pack your bag, take the elevator...) that go into one larger task ("getting to work") and reason about them. It's fundamentally a working memory/executive function deficit.
It's also shocking to me how every intent of leaving well and truly earlier than I thought can also fall apart. The lack of adrenaline in such situations allows a million distractions to creep in. "Oh, I can spend a few minutes to fix my makeup". "Oh, I haven't watered the plants in a while!" I can try to wall some of them off (I will NOT use the computer or look at my phone), but there's real limits.
The people who try to arrive 'just in time' are the ones this usually applies to though.
If you've ever worked at a place where you have a long commute you'll likely have noticed that the people who are consistently late are those who live closest.